On Tue, 18 Sep 2018 16:24:38 +0200 Eric Auger <eric.auger@xxxxxxxxxx> wrote: > From: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> > > In virtualization use case, when a guest is assigned > a PCI host device, protected by a virtual IOMMU on a guest, > the physical IOMMU must be programmed to be consistent with > the guest mappings. If the physical IOMMU supports two > translation stages it makes sense to program guest mappings > onto the first stage/level (ARM/VTD terminology) while to host > owns the stage/level 2. > > In that case, it is mandated to trap on guest configuration > settings and pass those to the physical iommu driver. > > This patch adds a new API to the iommu subsystem that allows > to bind and unbind the guest configuration data to the host. > > A generic iommu_pasid_table_config struct is introduced in > a new iommu.h uapi header. This is going to be used by the VFIO > user API. We foresee at least two specializations of this struct, > for PASID table passing and ARM SMMUv3. > > Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@xxxxxxx> > Signed-off-by: Liu, Yi L <yi.l.liu@xxxxxxxxxxxxxxx> > Signed-off-by: Ashok Raj <ashok.raj@xxxxxxxxx> > Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx> > Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx> > > --- > > In practice, I think it would be simpler to have a single > set_pasid_table function instead of bind/unbind. The "bypass" field > tells the stage 1 is bypassed (equivalent to the unbind actually). > On userspace we have notifications that the device context has > changed. Calling either bind or unbind requires to have an understand > of what was the previous state and call different notifiers. So to me > the bind/unbind complexifies the user integration while not bring much > benefits. > I don't have strong preference and I think having a single function makes sense. In VT-d2, the bind/unbind operation is a result of PASID cache invalidation from the guest. So there is no symmetrical bind/unbin user calls. > This patch generalizes the API introduced by Jacob & co-authors in > https://lwn.net/Articles/754331/ > > v1 -> v2: > - restore the original pasid table name > - remove the struct device * parameter in the API > - reworked iommu_pasid_smmuv3 > --- > drivers/iommu/iommu.c | 19 ++++++++++++++ > include/linux/iommu.h | 21 +++++++++++++++ > include/uapi/linux/iommu.h | 52 > ++++++++++++++++++++++++++++++++++++++ 3 files changed, 92 > insertions(+) create mode 100644 include/uapi/linux/iommu.h > > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > index 8c15c5980299..db2c7c9502ae 100644 > --- a/drivers/iommu/iommu.c > +++ b/drivers/iommu/iommu.c > @@ -1362,6 +1362,25 @@ int iommu_attach_device(struct iommu_domain > *domain, struct device *dev) } > EXPORT_SYMBOL_GPL(iommu_attach_device); > > +int iommu_bind_pasid_table(struct iommu_domain *domain, > + struct iommu_pasid_table_config *cfg) > +{ > + if (unlikely(!domain->ops->bind_pasid_table)) > + return -ENODEV; > + > + return domain->ops->bind_pasid_table(domain, cfg); > +} > +EXPORT_SYMBOL_GPL(iommu_bind_pasid_table); > + > +void iommu_unbind_pasid_table(struct iommu_domain *domain) > +{ > + if (unlikely(!domain->ops->unbind_pasid_table)) > + return; > + > + domain->ops->unbind_pasid_table(domain); > +} > +EXPORT_SYMBOL_GPL(iommu_unbind_pasid_table); > + > static void __iommu_detach_device(struct iommu_domain *domain, > struct device *dev) > { > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index 87994c265bf5..e56cad4863f7 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -25,6 +25,7 @@ > #include <linux/errno.h> > #include <linux/err.h> > #include <linux/of.h> > +#include <uapi/linux/iommu.h> > > #define IOMMU_READ (1 << 0) > #define IOMMU_WRITE (1 << 1) > @@ -185,6 +186,8 @@ struct iommu_resv_region { > * @domain_get_windows: Return the number of windows for a domain > * @of_xlate: add OF master IDs to iommu grouping > * @pgsize_bitmap: bitmap of all possible supported page sizes > + * @bind_pasid_table: bind pasid table > + * @unbind_pasid_table: unbind pasid table and restore defaults > */ > struct iommu_ops { > bool (*capable)(enum iommu_cap); > @@ -231,6 +234,10 @@ struct iommu_ops { > int (*of_xlate)(struct device *dev, struct of_phandle_args > *args); bool (*is_attach_deferred)(struct iommu_domain *domain, > struct device *dev); > + int (*bind_pasid_table)(struct iommu_domain *domain, > + struct iommu_pasid_table_config > *cfg); > + void (*unbind_pasid_table)(struct iommu_domain *domain); > + > unsigned long pgsize_bitmap; > }; > > @@ -292,6 +299,9 @@ extern int iommu_attach_device(struct > iommu_domain *domain, struct device *dev); > extern void iommu_detach_device(struct iommu_domain *domain, > struct device *dev); > +extern int iommu_bind_pasid_table(struct iommu_domain *domain, > + struct iommu_pasid_table_config > *cfg); +extern void iommu_unbind_pasid_table(struct iommu_domain > *domain); extern struct iommu_domain *iommu_get_domain_for_dev(struct > device *dev); extern int iommu_map(struct iommu_domain *domain, > unsigned long iova, phys_addr_t paddr, size_t size, int prot); > @@ -684,6 +694,17 @@ const struct iommu_ops > *iommu_ops_from_fwnode(struct fwnode_handle *fwnode) return NULL; > } > > +static inline > +int iommu_bind_pasid_table(struct iommu_domain *domain, > + struct iommu_pasid_table_config *cfg) > +{ > + return -ENODEV; > +} > +static inline > +void iommu_unbind_pasid_table(struct iommu_domain *domain) > +{ > +} > + > #endif /* CONFIG_IOMMU_API */ > > #ifdef CONFIG_IOMMU_DEBUGFS > diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h > new file mode 100644 > index 000000000000..babec91ae7e1 > --- /dev/null > +++ b/include/uapi/linux/iommu.h > @@ -0,0 +1,52 @@ > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > +/* > + * IOMMU user API definitions > + * > + * > + * This program is free software; you can redistribute it and/or > modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + */ > + > +#ifndef _UAPI_IOMMU_H > +#define _UAPI_IOMMU_H > + > +#include <linux/types.h> > + > +/** > + * SMMUv3 Stream Table Entry stage 1 related information > + * @s1contextptr: Context Descriptor Table GPA > + * @abort: shall the STE lead to abort > + * @s1fmt: STE s1fmt field as set by the guest > + * @s1cdmax: STE s1cdmax as set by the guest > + * @s1dss: STE s1dss as set by the guest > + * All field names match the smmu 3.0/3.1 spec (ARM IHI 0070A) > + */ > +struct iommu_pasid_smmuv3 { > + __u64 s1contextptr; > + __u8 bypass; > + __u8 abort; > + __u8 s1fmt; > + __u8 s1cdmax; > + __u8 s1dss; > +}; > + > +/** > + * PASID table data used to bind guest PASID table to the host IOMMU > + * Note PASID table corresponds to the Context Table on ARM SMMUv3. > + * > + * @version: API version to prepare for future extensions > + * @format: format of the PASID table > + * > + */ > +struct iommu_pasid_table_config { don;t you need some vendor neutral data such as * @base_ptr: PASID table pointer * @pasid_bits: number of bits supported in the guest PASID table, must be less * or equal than the host supported PASID size. > +#define PASID_TABLE_CFG_VERSION_1 1 > + __u32 version; > +#define IOMMU_PASID_FORMAT_SMMUV3 (1 << 0) > + __u32 format; > + union { > + struct iommu_pasid_smmuv3 smmuv3; > + }; > +}; > + > +#endif /* _UAPI_IOMMU_H */
